It has been proposed for optical lens devices to have a structure in which two lenses are assembled together through a lens barrel section in order to reduce an aberration of the optical lens generated by temperature change. The lens barrier section is made of resin. This lens barrel section expands and shrinks due to temperature change, and this expands and shrinks a gap between these lenses in accordance with temperature change so as to offset a generated aberration. (For example, see patent document 1.)
In addition, there are known techniques, for example one technique adjusts a refractive index of the lens by using an electric signal (for example, see patent document 2), and another technique adjusts a refractive index of a lens by moving the lens under the control of an actuator (for example, see patent document 3).